Preeclampsia is a multi-system disorder characterized by hypertension, edema and proteinuria impacting between 5 and 10% of pregnancies, typically after week 20. A subset of cases progress to severe preeclampsia, with symptoms comprising severe hypertension, severe proteinuria and/or evidence of dysfunctions of the nervous system, liver, kidneys as well as fetal growth restriction. Women with severe preeclampsia have elevated risk of life-threatening events, including placental abruption, acute renal failure, cerebral hemorrhage, hepatic failure or rupture, pulmonary edema, disseminated intravascular coagulation, and progression to grand mal seizures (eclampsia).
In the United States, preeclampsia/eclampsia is one of the leading causes of maternal death, while globally more than one in ten deaths related to obstetric complications is attributable to preeclampsia/eclampsia. As well as the extension of acute risk to the mother into the post-partum period until the complete delivery of the placenta, a number of long-term pathologies have been associated with preeclampsia.
While the presence, absence and severity of preeclampsia in previous pregnancies, family history, maternal age and a number of other conditions have been identified as risk factors, preeclampsia occurs in many nulliparous pregnancies without obvious predisposing factors. In addition, the diagnosis can be complicated by superimposition of preexisting hypertension as well as the drop in blood pressure often associated with early pregnancy. Both of these factors can confound the accurate establishment of a baseline blood pressure in some patients. Similarly, preexisting renal disease, which may or may not be exacerbated by pregnancy, can confound the establishment of an appropriate baseline measure for proteinuria. Some other conditions, including but not limited to gestational hypertension, can present as one or more of the signs and symptoms associated with preeclampsia, and collectively these together with preexisting renal disease and hypertension when confused with, or superimposed upon preeclampsia, pose challenges to the proper management of the pregnant patient.